BLAM! How-To Use The Halftone Pattern Filter

The Halftone Pattern filter can make activate your images from the mundane to the exciting! Here’s how to recreate an old comic-book style with it.

The Halftone Pattern filter (Filter –> Sketch –> Halftone Pattern…) is a really cool filter, evoking memories of old comics books and Sunday funnies. For art buffs, it is also a reminder of the work of Roy Lichtenstein (1923–1997), a major figure in the Pop Art movement which was prevalent in the 1950s and 1960s. In this How-To, I will show how to make an ordinary image look like it’s been printed in one of old comic books.

Figure 1: Warhol’s Campbell’s Soup Can.

In a homage to another Pop Art superstar, my test image will be Campbell’s Soup Can by Andy Warhol (1930–1987), a silkscreen that’s recognizable by anyone! You can work with an RGB or CMYK image, it doesn’t really matter, but since the comics have always been printed in CMYK I think that’s what I’m going to work with as well.

Step 1: You will be rotating channels in order to create the right screen angles when using the Halftone Pattern filter, so the first step is to use Canvas Size… (Image –> Canvas Size…) and adding a healthy amount of white space around your image; see Figure 2.

Figure 2: Adding white space for eventual rotations.

Step 2: Select the Cyan channel (Cmd/Ctrl-1, or click on the channel in the Channels palette) and select all (Cmd/Ctrl-A, or Select –> All).

Step 3: Cyan is traditionally printed with a 105-degree angle, and the Halftone Pattern filter always creates dots at a 45-degree angle, so rotate the channel -60 degrees.

Step 4: Open the Halftone Pattern filter (Filter –> Sketch –> Halftone Pattern…), set your settings and click OK. There are three settings to make:

• Size controls the size of your dot. For web images, the smallest sizes seem to work the best; anything larger tends to look like building blocks.
• Contrast controls the amount of contrast between dots. Maximum contrast will create the most realistic comic-book style, but you can also do some neat effects with halftones when the contrast is lower.
• Pattern Type controls what kind of pattern is made. You can use conventional dot patterns, but there is also a Circle pattern and Line pattern which can create some psychedelic effects!

For this exercise I went with the Dot pattern at minimum Size and maximum Contrast.

Figure 3: Detail of the halftone pattern in the cyan.

At this point you’ll see the Cyan channel at an angle and with a 45-degree dot screen (a detail is shown in Figure 3).

Step 5: Select All once more and rotate 60 degrees to realign the channel with the others. You’ll notice now the cyan screen is 105 degrees.

Step 6: It’s time to repeat steps 2 through 5 with the magenta and yellow channels. I won’t go through each step by step, but here are the angles to rotate each channel:

• Magenta (rotate -30 degrees; creates 75-degree angle)
• Yellow (rotate -45 degrees; creates 90-degree angle)

Figures 4 and 5 show the magenta and yellow with their proper halftone screen angles. We don’t perform this on the black channel because blacks are printed in the comics as line art on top of the color halftones. A black halftone will fill the entire image with a muddy mess.

Figure 4: The halftone pattern in the magenta.

Figure 5: The halftone pattern in the yellow.

Step 7: Select all channels to view (Cmd/Ctrl-~) and see the halftones come together (Figure 6). If the angles are right, you’ll see the distinctive “rosette” pattern. Crop to desired size.

Figure 6: The final product!

Dealing With Whites

Well, not quite. The problem with the Halftone Pattern filter is that it puts dots all over the image, including white, and what we end up with are whites that read as about a 50% gray. In a normal photographic image you aren’t going to deal much with the problem, because chances are your image is going to be filled with all kinds of colors throughout (if you’re shooting snow scenes, that changes things). But I opted to go with the Warhol can, which has a white background and also a white label, which means I’ve thrown dirt all over my image.

The method I use to get around the problem is a more precise selection using Color Range, a selection tool that can grab a range of colors in an image (or channel). With this tool we can select all the color in the channel and not the white, thus applying the halftone screens to just the color. So if you are in a situation like this one, using an image with a lot of white, insert another step between steps 3 and 4:

Step 3.5: Deselect (Cmd/Ctrl-D, or Select –> Deselect) and then choose Select –> Color Range…. The Color Range dialog box is too complex to be discussed in detail in this How-To, but a quick-and-dirty way to select the cyan pixels is to sample some in the image with the Eyedropper and then fiddle with the Fuzziness slider until the Selection preview shows a reversed image. It might be tricky, so expect to spend some time fiddling to get the right selection. You know you have it right when the Halftone Pattern filter creates a very light or no halftone pattern in the whites. When you’re satisfied, click OK.

Figure 7: The same technique, modified to account for heavy white space.

Figure 7 shows my image after using this technique. There’s not a lot of halftone pattern to speak of, since the red color is primary (and thus uses 100% magenta and yellow ink) but this is a truer representation of what you would have seen in those old comic books your mother has long since thrown out.